Local heat transfer distribution between smooth flat surface and impinging incompressible air jet from a chevron nozzle

• Published in: Experimental thermal and fluid science 2016-11, Vol.78, p.124-136
• Main Authors: Vinze, Ravish, Chandel, S., Limaye, M.D., Prabhu, S.V.
• Format: Article
• Language: English
• Subjects: Chevron; Heat transfer enhancement; Jet impingement; Nusselt number
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2016.05.017

•Influence of chevron on the local heat transfer is studied.•Thin foil heater technique is used to measure heat transfer.•Jets Reynolds number are maintained at 28,000, 35,000 and 40,000.•Correlations are proposed for local heat transfer. Influence of chevron nozzle on local heat transfer distribution over a flat plate impinged by incompressible jets is studied for Reynolds numbers of 28,000, 35,000 and 40,000. Ten different chevron nozzle configurations are studied with a pipe diameter of 10.8mm. Thin metal foil technique is used with IR camera to measure the wall temperature at nozzle to plate distances (z/d) from 1 to 10. An increase in the local Nusselt number by 26–38% compared to that with circular pipe is measured. It is observed that N10 nozzle (with number of chevron tips n=8 and chevron tip angle θ=10°) provides best heat transfer performance. A correlation for the average heat transfer is proposed in present study. A multiplication factor is also introduced to predict local Nusselt number for N10 nozzle.